Paste dispensing toothbrushes, such as those shown in U.S. Pat. No. 4,135,831 to Reitknecht, U.S. Pat. No. 4,269,207 to Konrad et al., and U.S. Pat. No. 4,201,490 to D'Angelo, are known in the prior art but have experienced only moderate success because of several limitations of their designs. A significant limitation of these designs is that they require, at a minimum, three steps to operate. Before these brushes can be used, the hole(s) opening into the bristles must be opened, a knob at the base of the brush must be turned to dispense toothpaste into the bristles and then finally the hole(s) must be closed again. These steps require multiple manipulations of the toothbrush thus making these brushes commercially undesirable compared to using inexpensive existing toothbrushes with a separate toothpaste container.
The prior paste dispensing toothbrushes generally dispense toothpaste by using a knob at the end of the brush which rotates a cylinder on a threaded shaft. This complicated mechanism consists of several parts, is expensive to manufacture and more prone to breaking. A need exists for a paste dispensing toothbrush which dispenses paste with an inexpensive, simpler, and easier to manufacture mechanism.
In designs which do not have a mechanical means for forcing the toothpaste from the paste container, such as those which have a collapsible paste container, the units do not provide for positive dispensing of the paste and are susceptible to inadvertent dispensing of paste such as when carried during traveling. Thus, a need exists for a paste dispensing toothbrush which overcomes the limitations found in the prior art designs.